1. Field of the Invention
The invention relates to an electrical socket, more particularly to an electrical socket that is used for recharging electronic equipment.
2. Description of the Related Art
Referring to FIGS. 1 to 3, a conventional electrical socket 1 is adapted to be mounted on a circuit board (not shown), and is used for receiving a hollow plug 2 of an electronic equipment that is to be recharged. The plug 2 includes an engaging end portion 20 having an outer surface formed with an annular groove 21. The conventional electrical socket 1 includes a socket body 11, a central terminal pin 12 fixed within the socket body 11, a first terminal 13 connected fixedly to a lateral side of the socket body 11 and connected electrically to the central terminal pin 12, a second terminal 14 inserted into the socket body 11, and a spring terminal piece 15 adjacent to the second terminal 14.
The socket body 11 includes a wall unit 111 that defines a plug hole 112 for receiving the plug 2 of the electronic equipment therein, and a receiving recess portion 113 that is in communication with the plug hole 112. The plug hole 112 has a diameter, which is much larger than that of the engaging end portion 20 of the plug 2, and has an open end 1121 and a closed end 1122 opposite to the open end 1121. The first and second terminals 13, 14 are isolated electrically from each other. The spring terminal piece 15 includes a positioning portion 151 positioned on the socket body 11, a limiting portion 152 abutting releasably against the second terminal 14, and a curved movable portion 153 interconnecting the positioning and limiting portions 151, 152 and extending into the plug hole 112.
Before the plug 2 of the electronic equipment is inserted into the plug hole 112 in the socket 1, the limiting portion 152 of the spring terminal piece 15 is in electrical contact with the second terminal 14. In actual practice, the spring terminal piece 15 and the second terminal 14 are connected electrically to a light source (not shown), such as a light emitting diode, so that on/off operation of the light source is controlled by electrical connection and disconnection of the spring terminal piece 15 and the second terminal 14.
Referring to FIG. 3, when the plug 2 is inserted into the plug hole 112, it is sleeved directly on the central terminal pin 12 so as to connect electrically with the first terminal 13, thereby permitting recharging of the electronic equipment. The movable portion 153 of the spring terminal piece 15 is pressed downwardly by the plug 2 at this moment so as to move the limiting portion 152 of the spring terminal piece 15 away from the second terminal 14 so that the light source is turned off. When the engaging end portion 20 of the plug 2 is disposed at the closed end 1122 of the plug hole 112, the movable portion 153 of the spring terminal piece 15 engages the groove 21 in the engaging end portion 20 of the plug 2, thereby preventing removal of the plug 2 from the central terminal pin 12. At this moment, the electronic equipment can be recharged.
However, in actual practice, the spring terminal piece 15 of the conventional electrical socket 1 easily experiences fatigue due to frequent plugging and removal of the plug 2 with respect to the electrical socket 1, such that the plug 2 is likely to loosen undesirably from the electrical socket 1. Furthermore, the service life of the conventional electrical socket 1 is shortened.
Therefore, the main object of the present invention is to provide an electrical socket that is capable of overcoming the aforementioned drawbacks of the prior art.
According to the present invention, an electrical socket is adapted for receiving a hollow plug of an electronic equipment therein so as to permit recharging of the electronic equipment. The plug includes an engaging end portion that has an outer surface formed with an annular groove. The socket comprises a socket body made of an insulating material, a central terminal pin, and a curved spring terminal piece. The socket body includes a front surface, a bottom surface, and a protrusion. The bottom surface has a dovetail groove, which is adapted to receive the hollow plug therein and which has an open end that is formed in the front surface of the socket body, and a closed end opposite to the open end of the dovetail groove. The dovetail groove is defined by an inner wall surface, and has a rear end retaining portion that is proximate to the closed end of the dovetail groove and that is adapted to receive the engaging end portion of the plug fittingly therein. The protrusion protrudes from the inner wall surface, and is adapted to engage the annular groove in the plug when the plug is inserted into the socket body. The central terminal pin is fixed within the socket body, extends along the center of the dovetail groove, and is adapted to be inserted into the plug so as connect electrically therewith, thereby permitting recharging of the electronic equipment. The curved spring terminal piece is disposed in the socket body, and has an end fastened to the socket body, and a movable portion that is adapted to engage the groove in the plug so as to be adapted to press the plug against the protrusion such that the plug is clamped between the protrusion and the terminal pin.